NF2 and sensorineural hearing loss disorder: However, two classes of drugs have demonstrated some efficacy in ameliorating SNHL due to VS via unknown mechanisms: bevacizumab, a monoclonal antibody against vascular endothelial growth factor A (VEGF-A) improves hearing in 54% of NF2-associated VS3, whereas corticosteroids can improve sudden SNHL associated with sporadic and NF2-associated VS4.